The present invention relates to a new and improved construction of apparatus for the contactless transmission of electrical signals between a first part or component containing a first conductor arrangement and a second part or component rotatable relative thereto about a predetermined axis and containing a second conductor arrangement coupled in a contactless fashion with the first conductor arrangement.
In order to transmit electrical signals between relatively rotating parts it is well known to use slip rings containing electrical contact means. However, such are associated with the drawback that there can arise transmission errors due to interruption of the current or fluctuations in the resistances, caused by dust, carbon particles or grit, grease, oil and mechanical vibrations. These shortcomings can be overcome by resorting to the use of contactless transmission equipment.
Thus, for instance, in Swiss Patent No. 598,574, granted Nov. 15, 1977, there is disclosed an apparatus for the contactless transmission of alternating-current signals between two relatively rotating parts which possess two transformers each having two respective windings, and at each transformer the one winding is rotatably arranged relative to the other winding. With such apparatus there cannot be obtained high threshold frequencies governed by the high inductances of the transformer windings. Additionally, in order to avoid cross-talk there are required large distances between the transformers. This makes it impossible to construct a compact piece of equipment having small spatial requirements. A further shortcoming resides in the fact that the assembly, repair and exchange of the parts is both difficult and time-consuming.